North Korea could perform its first nuclear test in five years to mark the 110th anniversary of the birth of the country’s founder, Kim Il-sung, on April 15, a senior U.S. official has warned. Sung Kim, special representative for North Korea policy at the U.S. state department, told reporters Wednesday: “We are worried that in connection with the upcoming anniversary, the DPRK may be tempted to take another provocative action. I don’t want to speculate too much, but I think it could be another missile launch, it could be a nuclear test.” Since 2006, the hermit state has carried out six nuclear tests. The tests stopped in 2017 ahead of Kim Jong Un’s summit with Donald Trump. Earlier this week, Kim Jong Un’s sister embarked on a war of words with South Korea after a politician there talked up the possibility of a pre-emptive strike on the North.